Marius otto and albert verley



(No Model.)

M. OTTO & A. VERLEY.

MANUFACTURE OF VAN'ILLIN'. No. 553,593. Patented Jan. 28, 1896.

UNITED STATES PATENT OFFICE.

MARIUS OTTO AND ALBERT VERLEY, OF COURBEVOIE, FRANCE.

MANUFACTURE OF VANlLLlN.

SPECIFICATION forming part of Letters Patent No. 553,593, dated January28, 1896. Application filed July 8, 1895. Serial No. 555,333. (Nospecimens.)

To all whom it may concern:

Be it known that we, MARIUS OTTO and ALBERT VERLEY, chemists, citizensof the French Republic, residing at 7 Quai de Seine, Courbevoie,(Seine,) in the Republic of France, have invented certain Improvementsin the Manufacture of Vanillin, of which the following is aspecification.

The object of our invention is to obtain vanillin in a cheap andexpeditious manner by synthesis. To effect this object we oxidize asolution of isoeugenate of soda (or other convenient base) and treat theresulting product with an acid and separate the vanillin so produced.This oxidation may be effected by electrolyzing an alkaline solution ofisoeugenate of soda, either cold or warm, preferably at the temperatureof an ordinary water-bath. This electrolysis may be convenientlyeffected by placing the solution of isoeugenate of soda in a vesselstanding in a water-bath and connected with a vessel containing asolution of soda by a U shaped tube, which passes through the sides ofthe respective vessels at a convenient height above the bottoms of thevessels. Electrodes, preferably of platinum, are placed in the vesselsand connected to the respective poles of a source of electricity, theelectrode in the vessel containing the solution of isoeugenate of sodabeing at the bottom and connected by an insulated wire, so that thecurrent may pass through the whole mass of the fluid and oxidize theisoeugenate of soda. By this arrangement the oxidation is effectedwithout any substantial mixing of the two liquids. The reaction whichtakes place is the oxidation of the isoeugenate of soda, as beforeexplained, and thereby its change into vanillate of soda. The subsequenttreatment with an acid (which may, for instance, be oxalic acid orsulphuric acid diluted with its own volume of water) forms a sodium saltin accordance with the acid used and sets free the vanillin.

To ascertain if the oxidation of the isoeugenate of soda is complete thequantity of hydrogen which is set free at the negative pole may bemeasured and from it be deduced the quantity of oxygen set free at thepositive pole; or the test may be simply made by reference to thequantity of oxygen at the positive pole; but the invention is notlimited, of course, in any way to any particular test.

The accompanying drawing illustrates diagrammatically an apparatus whichmay conveniently be used in carrying out our process.

The solution of isoeugenate of soda is placed in the vessel A. In thevessel B we place a solution of soda serving merely as a conductorbetween the positive electrode a and the negative electrode b. Thesevessels are connected by a U-shaped tube O at a convenient distanceabove the bottoms of the vessels, so that while the liquid forms acontinuous path closing the internal circuit of the electrolytic baththere will be no mingling of the products formed around the respectiveelectrodes. This arrangement is adopted for economy and to increase theyield from the operation. The products of oxidation formed around thepositive electrode are those utilized in our process of making vanillin,and it is preferred that they should not be contaminated by the productsformed at the negative pole. The electric circuit is completed byconnecting the terminals of electrodes at and I) respect ively with thepositive and negative poles of an electric generator, preferably onefurnishinga continuous current of low tension.

When the oxidation is judged to be complete the solution is treated withan acid which sets free the vanillin. It can be puritied with bisulphideof soda and by repeated crystallization, as may be found requisite.

We claim-- The manufacture of vanillin by subjecting a solution ofiso-eugenate of soda or other base to electrolysis and then treating bymeans of an acid.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

. MARIUS OTTO.

A. VERLEY. 'Witnesses:

J OINELLERMET, G. DEoHAus.

